The Serve, Know the Basics
Practice with your doubles partner or one of your singles friends.
by Mat Galemmo,

The serve, with all its varieties and nuances, can be difficult to consistently maintain. Whenever you are struggling with your serve, it is helpful to key on a few basic points, rather than obsessing over too many elements. Let your body do the job you've trained it to, and concentrate on these simple keys:

Grip: Continental, you should be able to bounce the ball with the edge of your racket.

Stance: Stand sideways to the net with your feet comfortably apart and your weight on the back foot. You should be able to draw a diagonal line from the toes of your back foot to the toes of your front foot to the service court. You shoud hold the racket in front of your body, arms in close, and supported with your free hand. The racket is on edge and pointing to the service box.

Backswing and toss: Down together, up together rhythm. The toss is straight up from your extended left arm. The racket swings down past the right hip and then up behind the back.

Point of Contact: Reach up as far as you can, making contact above your head, slightly in front and to the right.

The Slice Serve: The primary purpose of the slice serve is to pull the opponent wide or to have the ball jam the opponent. The lower and further to the right one makes the toss, the more effective the slice becomes. Using the example of the clockface, the racket should "bypass" the ball at 3 o'clock.

The Spin Serve: The spin serve is really a combination of the slice and the topspin or American twist serve. The stroke can easily be disguised by imparting both overspin and slice at the same time, the ball can either curve quite wide or kick high enough to present an awkward shot for the receiver. By using the face of the clock, the racket should "bypass" the ball at 1 o'clock.